Answer: 0.875
Step-by-step explanation:
The answer that has already been given is perfect in and by itself. I just want to give you some methods for doing these type of questions so that you won’t stagger when you see these type of questions in exams (like the SAT).
Whenever you see such questions, remember the following things. These are conversions of English words to Mathematical tools.
What
=
Any variable like
x
Percent / Percentage / %
=
Divide by 100
of
=
Multiply
is
=
Put an equal to (
=
) sign
I’ll give you an example through a question.
What percent of 200 is 5?
Ans: Replace English words by mathematical tools according to the rules I told you.
x
( What) /100 ( percent)
×
( of) 200
=
( is) 5
In a refined form,
x
100
×
200
=
5
Calculate x. On calculating, x comes out to be
2.5
So, 2.5 percent of 200 is 5.
Now your question is actually very simple if you follow my rules.
You want 87.5%. By the rules, % means divided by 100. So
87.5
%
=
87.5
100
and now using the same strategy, Ans:
875
1000
Disregard the next section if you know how to convert a decimal to a fraction
Section Starts
First, I’ll write the decimal form. Whenever you divide by a number that is in form of 1 followed by
n
number of zeroes. (here 1 is followed by 2 zeroes), you should shift the decimal point to the left side by n places.
In this case, shift decimal point in 87.5 to the left by 2 places. So this becomes 0.875.
This is the answer in decimal point.
Now simultaneously, I’ll teach you how to convert a decimal into a fraction.
Here, you see 2 types of “numbers”. One to the left side of the decimal point and one to the right side of the decimal point.
Here, left side of decimal point is 0 and right side of decimal point is 875.
Count the number of digits in the number to the right side of the decimal point (Here, the number of digits is 3)
Remove the decimal point and divide the number by a number formed by 1 followed by the “digits” we obtained (i.e. 3).
So, 875/1000. Simplify this, and you get your answer.
![\frac{V_1}{V_2}=k^3 \\ \\ \frac{320 \ cm^3}{1080 \ cm^3}=k^3 \\ \frac{8}{27}=k^3 \\ k=\sqrt[3]{\frac{8}{27}} \\ \boxed{k=\frac{2}{3}} \Leftarrow \hbox{answer B}](https://tex.z-dn.net/?f=%5Cfrac%7BV_1%7D%7BV_2%7D%3Dk%5E3%20%5C%5C%20%5C%5C%0A%5Cfrac%7B320%20%5C%20cm%5E3%7D%7B1080%20%5C%20cm%5E3%7D%3Dk%5E3%20%5C%5C%0A%5Cfrac%7B8%7D%7B27%7D%3Dk%5E3%20%5C%5C%0Ak%3D%5Csqrt%5B3%5D%7B%5Cfrac%7B8%7D%7B27%7D%7D%20%5C%5C%0A%5Cboxed%7Bk%3D%5Cfrac%7B2%7D%7B3%7D%7D%20%5CLeftarrow%20%5Chbox%7Banswer%20B%7D)